Only.
 

A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous

但  Only, merely, whenever. Yet, still, but (kevala, mātra).

kevala : [adj.] lonely; unmixed; whole; entire.

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

Kevala (adj. -- adv.) [cp. Lat. caelebs=*caivilo -- b˚ to live by oneself, i. e. to live in celibacy, perhaps also, Goth. hails, Ohg. heil, E. whole] expression of the concept of unity and totality: only, alone; whole, complete; adv. altogether or only -- 1. ˚ŋ (adv.) (a) only=just: k. tvaŋ amhākaŋ vacanaŋ karohi "do all we tell you" PvA 4; -- only=but, with this difference: VvA 203, 249; -- k. . . . vippalapati he only talks PvA 93; <-> and yet: "sakkā nu kiñci adatvā k. sagge nibbattituŋ? " is it possible not to give anything, and yet go to heaven? kevalaŋ mano -- pasāda -- mattena only by purity of mind DhA i.33; kevalaŋ vacchake balava -- piyacittatāya simply by the strong love towards the babycalf Vism 313; (b) alone: k. araññaŋ gamissāmi VvA 260; -- exclusive Miln 247. -- na k. . . . atha kho not only . . . but also VvA 227. -- 2. whole, entire Sn p. 108; Cp. i.1019; Pv ii.63 (=sakala PvA 95); Vism 528 (=asammissa, sakala); Pv ii.63 (=sakala PvA 95). <-> k.>akevala entire>deficient M i.326. ˚ŋ entirely, thoroughly, all round: k˚ obhāsenti VvA 282.
   -- kappa a whole kappa Sn pp. 18, 45, 125; KhA 115; VvA 124, 255. -- paripuṇṇa fulfilled in its entirety (sakala DA i.177) of the Doctrine; expld also at Nett 10.

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

kevala: a. 唯一

巴漢辭典 編者：(斗六) 廖文燦