Definition: name of an important kind of compound words similar to the compound word तत्पुरुष i.e. (तस्य पुरुषः), and hence chosen as the name of such compounds by ancient grammarians before Panini. Panini has not defined the term with a view to including such compounds as would be covered by the definition. He has mentioned the term तत्पुरुष in II.1.22 as Adhikara and on its strength directed that all compounds mentioned or prescribed thereafter upto Sutra II.2.22 be called तत्पुरुष. No definite number of the sub-divisions of तत्पुरुष is given;but from the nature of compounds included in the तत्पुरुष-अधिकार, the sub-divisions विभक्तितत्पुरुष cf. P.II.1.24 to 48, समानाधिकरणतत्पुरुष cf. P. II.1.49 to 72 (called by the name कर्मधारय; acc.to P.I. 2. 42), संख्यातत्पुरुष (called द्विगु by P.II.1.52), अवयत्रतत्पुरुष or एकदेशितत्पुरुषं cf. P.II.2.1-3, ब्यधिकरणतत्पुरुष cf. P. II 2.5, नञ्तत्पुरुष cf. P.II.2.6, उपपदतत्पुरुष cf. P. II.2.19, प्रादितत्पुरुष cf. P.II.2 18 and णमुल्तत्पुरुष cf.P.II.2.20 are found mentioned in the commentary literature on standard classical works. Besides these, a peculiar tatpurusa compound mentioned by'Panini in II.1.72, is popularly called मयूरव्यंसकादिसमास. Panini has defined only two out of these varieties viz. द्विगु as संख्यापूर्वो द्विगुः P.II. 1.23, and कर्मधारय as तत्पुरुषः समानाधिकरणः कर्मधारयः P. I.2.42. The Mahabhasyakara has described तत्पुरुष as उत्तरपदार्थप्रधानस्तत्पुरुषः: cf. M.Bh. on II.1.6, II.1.20, II.1.49, etc., and as a consequence it follows that the gender of the tatpurusa compound word is that of the last member of the compound; cf. परवल्लिङ द्वन्द्वतत्पुरुषयोः P. II.4. 26; cf also तत्पुरुषश्चापि कः परवल्लिङं प्रयोजयति । यः पूर्वपदार्थप्रधानः एकदेशिसमासः अर्धपिप्पलीति । यो ह्युत्तरपदार्थप्रधानो दैवकृतं तस्य परवल्लिङ्गम्, M. Bh. on II.4.26. Sometimes, the compound gets a gender different from that of the last word; cf. P.II.4.19-31, The tatpurusa compound is optional as generally all compounds are, depending as they do upon the desire of the speaker. Some tatpurusa compounds such as the प्रादितत्पुरुष or उपपदतत्पुरुष are called नित्य and hence their constitutent words, with the case affixes applied to them, are not noticed separately; cf. P.II.2.18,19, In some cases अ as a compound-ending (समासान्त) is added: e.g. राजघुरा, नान्दीपुरम्; cf. P. V.4.74; in some cases अच् (अ) is added: cf. P.V-4 75 o 87: while in some other cases टच् (अ) is added, the mute letter ट् signifying the addition of ङीप् (ई) in the feminine gender; cf.P.V.4. 91-1 12. For details See p.p. 270-273 Mahabhasya Vol.VII published by the D. E. Society, Poona.