From WordNet (r) 2.0 (August 2003) [wn]:
authorise
v 1: give or delegate power or authority to; "She authorized her
assistant to sign the papers" [syn: empower,
authorize]
2: grant authorization or clearance for; "Clear the manuscript
for publication"; "The rock star never authorized this
slanderous biography" [syn: authorize, pass, clear]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
authorise \authorise\ v.
1. grant authorization or clearance for. Same as authorize.
Syn: authorize, pass, clear, permit officially.
[WordNet 1.5]