thambha : [m.] a pillar; post; a clump of grass; obduracy.

A.P. Buddhadatta Mahathera, Concise Pali-English and English-Pali Dictionary [available as digital version from Metta Net, Sri Lanka]

Thambha [see etym. under thaddha; occasionally spelt thamba, viz. A i.100; M i.324; PvA 186, 187] 1. a pillar, a post Vin i.276; D i.50 (majjhimaŋ ˚ŋ nissāya); ii.85 (id.); Sn 214; Vv 782 (veḷuriya˚, of the pillars of a Vimāna); Pv iii.31 (id.); DhA iv.203; VvA 188 (+tulā -- gopānasī); PvA 186. -- 2. (fig.) in all meanings of thaddha, applied to selfishness, obduracy, hypocrisy & deceit; viz. immobility, hardness, stupor, obstinacy (cp. Ger. "verstockt"): thambho ti thaddha -- bhāvo SnA 288, 333; th. thambhanā thambhittaŋ kakkhaliyaŋ phāruliyaŋ ujucittatā (an˚?) amudutā Vbh 350. -- Often combd w. māna (=arrogance), freq. in set sāṭheyyaŋ th. sārambho māno, etc. A i.100, 299=Nd2 under rāga=Miln 289; cp. M i.15. -- A iii.430 (+māna); iv.350, 465 (+sāṭheyya); Sn 245 (+mada), 326, 437 (as one of Māra's combatants: makkho th. te aṭṭhamo); J i.202. -- 3. a clump of grass M i.324; cp. thambhaka.

Pali-English Dictionary, TW Rhys Davids, William Stede,