1 رَدَأَ الحَائِطَ  , [aor. رَدَاَ , inf. n. رَدْءٌ,] He supported, propped, or stayed, the wall, (ISh, T, K,) by means of a piece of timber or wood, or a buttress or the like, to prevent its falling; (ISh, T;) as also ↓ ارادأهُ : (Yoo, T, K:) or رَدَأَ الحَائِطَ بِبِنَآءٍ [he supported the wall by a structure;] he attached a structure to the wall. (M.) ― -b2- Hence, (T,) رَدَأَهُ بِهِ He strengthened and supported him, or it, by means of it, (Lth, T, M, * K,) namely, a person by a thing, (Lth, T,) or a thing by a thing, (M,) like as one strengthens and supports a wall by means of a structure which he attaches thereto; (T;) as also ↓ ارادأهُ . (T, * K.) And رَدَأَهُ, (Mgh, TA,) inf. n. رَدْءٌ, (Mgh,) He helped, aided, or assisted, him; (Mgh, TA;) as also ↓ اردأهُ : (T, S, M, Msb, K:) and رَدَأْتُهُ and ↓ أَرْدَأْتُهُ , (T,) or بِنَفْسِى ↓ أَرْدَأْتُهُ , (S,) I was, or became, a helper, an aider, or an assistant, to him. (T, S.) ― -b3- Hence also, (i. e., from ردأ الحَائط,) رَدَأَ الإِِبِلَ (tropical:) He took good care of the camels, (A, K, TA,) in tending and pasturing them. (A, TA.) ― -b4- And رَدَأَهُ بِحَجَرٍ He cast a stone at him; (M, K;) like [رَدَاهُ, mentioned in art. ردى, and] دَرَأَهُ. (M.) -A2- رَدُؤَ, aor. رَدُاَ , inf. n. رَدَآءَةٌ, (T, S, M, K, &c.,) for which one should not say رَدَاوَةٌ; (T;) and Th mentions also رَدَأَ and رَدِىءَ as syn. with رَدُؤَ, but these are strange; and more strange is what is said in the Msb, namely, رَدَا aor. يَرْدُو, part. n. رَدِىٌّ, [as a dial. var.,] asserted by IDrst, in the Expos. of the Fs, to be erroneous, and peculiar to the vulgar; (MF, TA;) It (a thing, T, S, M, Msb,) [and he, see رَدِىْءٌ, its part. n.,] was, or became, bad, corrupt, vitious, depraved, or the like; (S, M, Msb, * K;) or of no rank, or estimation; low, ignoble, vile, or mean; (Msb;) [disapproved, disliked, hated, or abominable: (see رَدِىْءٌ:)] and he was, or became, weak, and impotent, so as to be in want or need. (TA from the Expositions of the Fs.) 2 رَدَّاَ see the next paragraph. 4 اردأهُ ذ : see 1, in five places. ― -b2- Also He settled, established, or confirmed, him, or it, (K, TA,) in his, or its, state. (TA.) ― -b3- He stilled, or quieted, him, or it. (K.) ― -b4- And He let it down; namely, a veil, or curtain. (K.) -A2- Also He rendered it bad, corrupt, vitious, depraved, or the like; (S, K;) namely, a thing; said of a man; (S;) [and ↓ ردّآهُ is used in the same sense: (see 1 in art. جشب:)] he made, or asserted, or held, it (a thing) to be رَدِىء [or bad, &c.]. (TA.) ― -b2- And اردأ signifies He did a thing, or a deed, that was رَدِىْء [or bad, &c.]: or he met with, or experienced, (أَصَابَ,) a thing that was رَدِىْء. (M, K.) -A3- اردأ عَلَى غَيْرِهِ It exceeded another thing; as also أَرْدَى: (M:) [or the latter only:] accord. to IAar, one says اردأ عَلَى السِّتِّينَ, with ', (M,) and, accord. to Lth, على الخَمْسِينَ, (TA,) and, [accord. to F,] على مِائَةٍ, (K,) meaning He exceeded [the age of sixty, and fifty, and a hundred]: (M, K, TA:) but Az says that اردأ, with ', [in these phrases,] though authorized by Lth, is wrong; (TA;) and accord. to A' Obeyed, one says أَرْدَيْتُ. (M. [It is added, however, in the M, that اردأ may perhaps be also used in poetry in the same sense without the prep. على.]) 5 تَرَدَّؤُوا  They helped, aided, or assisted, one another. (Lth, M, TA.) رِدْءٌ  A buttress, or the like, by means of which a wall is strengthened and supported. (T.) [This is the primary signification. See also رِدٌّ, in art. رد.] ― -b2- [Or] the primary meaning is A thing by means of which one is helped, aided, or assisted; such as the دِفْء [or thing by which one is rendered warm, or protected from the cold wind]. (Bd in xxviii. 34; where it has the meaning next following, as is said in the T and S.) ― -b3- A helper, an aider, or an assistant. (T, S, M, Mgh, Msb, K.) You say, فُلَانٌ رِدْءٌ لِفُلَانٍ Such a one is an aider and a strengthener to such a one. (T.) ― -b4- And i. q. مَادَّةٌ [app. as meaning An accession; or a thing that is added, whatever it be, to another thing]. (M, K.) ― -b5- And (tropical:) i. q. عِدْلٌ [i. e. A burden that balances another burden on the other side of a beast]; (T, TA;) so called because one such ردء supports another: (TA:) and a heavy عِدْل: (T, K, TA:) pl. أَرْدَآءٌ. (T, TA.) رِدَآءٌ  : see art. ردى. رَدِىْءٌ  , applied to a thing, (T, S, M, Msb,) and to a man, (M, TA,) Bad, corrupt, vitious, depraved, or the like; (S, M, Msb, * K;) of no rank, or estimation; low, ignoble, vile, or mean; (Msb;) disapproved, disliked, hated, or abominable: and weak, and impotent, so as to be in want or need: and accord to the Msb, one says also رَدِىٌّ; [there said to be a dial. var.;] but this is asserted by IDrst, in the Expos. of the Fs, to be erroneous, and peculiar to the vulgar: (TA:) pl. أَرْدِئَآءُ, with two hemzehs, (M, K,) applied to a people, or company of men. (M.) [ أَرْدَأُ ذ Worse, and worst; more, and most, corrupt &c.] مِرْدَأَةٌ  A stone which a strong man can hardly lift with both his hands; (TA;) as also مِرْدَاةٌ. (ISh, TA in art. ردى.) Credit: Lane Lexicon