sū́tra n. (accord. to g. ardhacādi also m.; fr. √ siv, ‘to sew’, and connected with sūci and sūnā) a thread, yarn, string, line, cord, wire, [AV.] &c. &c.
a measuring line (cf. -pāta), [Hariv.]; [VarBṛS.] &c.
the sacred thread or cord worn by the first three classes (cf. yajñopavīta), [BhP.]
a girdle, [ib.]
a fibre, [Kālid.]
a line, stroke, [MBh.]; [VarBṛS.]; [Gol.]
a sketch, plan, [Rājat.]
that which like a thread runs through or holds together everything, rule, direction, [BhP.]
a short sentence or aphoristic rule, and any work or manual consisting of strings of such rules hanging together like threads (these Sūtra works form manuals of teaching in ritual, philosophy, grammar &c.: e.g. in ritual there are first the Śrauta-sūtras, and among them the Kalpa-sūtras, founded directly on Śruti q.v.; they form a kind of rubric to Vedic ceremonial, giving concise rules for the performance of every kind of sacrifice [[IW. 146] &c.]; other kinds of Ś° works are the Gṛhya-sūtras and Sāmayācārika or Dharma-sūtras i.e. ‘rules for domestic ceremonies and conventional customs’, sometimes called collectively Smārta-sūtras [as founded on smṛti or ‘tradition’, see smārta]; these led to the later Dharmaśāstras or ‘law-books’ [[IW. 145]]; in philosophy each system has its regular text-book of aphorisms written in Sūtras by its supposed founder [[IW. 60] &c.]; in Vyākaraṇa or grammar there are the celebrated Sūtras of Pāṇini in eight books, which are the groundwork of a vast grammatical literature; with Buddhists, Pāśupatas &c. the term Sūtra is applied to original text books as opp. to explanatory works; with Jainas they form part of the Dṛṣṭivāda), [IW. 162] &c.
a kind of tree, [Divyāv.]