Dictionary Definition:
gurú mf(vii)n. (cf. girí
• comp. gárīyas, once ○yas-tara, guru-tara, superl. gariṣṭha, gurutama, ss. vv.) heavy, weighty (opposed to laghú) RV. i, 39, 3 and iv, 5, 6 AV. &c. (g. śauṇḍâdi Gaṇar. 101)
• heavy in the stomach (food), difficult to digest MBh. i, 3334 Suśr.
• great, large, extended, long Yājñ. ( -kratu) Bhartṛ. &c
• (in prosody) long by nature or position (a vowel) Prāt. (a vowel long both by nature and by position is called garīyas RPrāt. xviii, 20) Pāṇ. 1-4, 11 and 12
• high in degree, vehement, violent, excessive, difficult, hard RV. MBh. &c
• grievous Megh. 80
• important, serious, momentous MBh.&c
• valuable, highly prized Yājñ. ii, 30 (guru = garīyas) &c
• haughty, proud (speech) Pañcat.
• venerable, respectable
• m. any venerable or respectable person (father, mother, or any relative older than one's self) Gobh. ŚāṅkhGṛ. Mn. &c
• a spiritual parent or preceptor (from whom a youth receives the initiatory Mantra or prayer, who instructs him in the Śāstras and conducts the necessary ceremonies up to that of investiture which is performed by the Ācārya Yājñ. i, 34) RPrāt. ĀśvGṛ. PārGṛ. Mn. &c
• the chief of (gen. or in comp.) Cāṇ. Ragh. ii, 68
• (with Śāktas) author of a Mantra
• 'preceptor of the gods', Bṛihaspati Mn. xi
• (hence) the planet Jupiter
Jyot. VarBṛS. Bhartṛ. &c
• 'Pāṇḍu-teacher', Droṇa L.
• Prabhā-kara (celebrated teacher of the Mīmāṃsā, usually mentioned with Kumārila) SŚaṃkar. vi, 50 ; xv, 157
• (= dharma) 'venerable', the 9th astrological mansion VarBṛS. i, 16
• Mucuna pruritus L.
• N. of a son of Saṃkṛiti BhP. ix, 21, 2 du. parents MBh.
• m. pl. parents and other venerable persons Mn. iv Vikr. v, 10 Kathās.
• a honorific appellation of a preceptor (whose N. is also put in the pl.), Jain Hit.
• (vii), f. 'venerable woman', a mother Āp. i, 21, 9
• 'great (with child)', pregnant, a pregnant woman L.
• the wife of a teacher W.
• [cf. ? ; Lat. gravis ; Goth. kauriths ; Lith. giéras.