شَكٌّ
1.
[used as a subst.] signifies Doubt; (Msb; [see 1;]) or the opposite of
يَقِينٌ; (S, O, Msb, K;) by which explanation is meant a wavering or
vacillation in opinion between two things, whether they be equal [in probability] or such that one of them outweighs [therein] the other; or, as the expositors explain its meaning in the Qur'an, 10:94, uncertainty: (Msb:) or a wavering or vacillation in opinion, between two inconsistent things, without making either of them to outweigh the other in the estimation of him who conceives the
شَكّ: or, as some say, a pausing, or hesitation, between two extremes that are equal [in probability], without the mind's inclining to either of them: when one of them is made to outweigh, without the other's being rejected, it is ظَنٌّ: (KT:) according to Er-Rághib, it is the alternation, or confusedness, of two inconsistent things, in the judgment of a man, and their being equal: this is sometimes because of there being two indications, equal in his judgment, of the two inconsistent things; or of there being no indication thereof: and sometimes it relates to the question whether a thing be, or be not; and sometimes, to the question of what kind it is; and sometimes, to some of its qualities; and sometimes, to the accident that is the cause of its being: it is a species of جَهْل; but is more special than this; for جهل is sometimes the utter nonexistence of knowledge of the two inconsistent things; so that every شكّ is جهل, but every جهل is not شكّ: (TA:) according to some, the primary meaning is a state of commotion, or disturbance, of the heart and mind: (Msb:) plural شُكُوكٌ. (K.)
2.
[Hence, يَوْمُ الشَّكِ
The day of which one doubts whether it be the last of one month or the first of the next month: and generally, whether it be the last of Shaabán or the first of Ramadán; and to fast on this day is forbidden.]
3.
Also A small crack in a bone. (K.)
4.
And A seam, or line of sewing, of a garment. (L in article صوح.)
5.
[And according to Freytag, A coat of mail composed of narrow rings: but he names no authority for this.]