The Collaborative International Dictionary of English v.0.48:
Defendable \De*fend"a*ble\ (d[-e]*f[e^]nd"[.a]*b'l), a. [Cf. F. d['e]fendable.] Capable of being defended; defensible. [R.] [1913 Webster]WordNet (r) 3.0 (2006):
defendable adj 1: capable of being defended [syn: defendable, defensible]