Adjective

(en adjective)

Having the faculty of reason; endued with reason; rational.

a reasonable being

Just; fair; agreeable to reason.

* {{quote-news

, year=2012 , date=May 27 , author=Nathan Rabin , title=TV: Review: THE SIMPSONS (CLASSIC): “New Kid On The Block” (season 4, episode 8; originally aired 11/12/1992) , work=The Onion AV Club citation , page= , passage=The episode also opens with an inspired bit of business for Homer, who blithely refuses to acquiesce to an elderly neighbor’s utterly reasonable request that he help make the process of selling her house easier by wearing pants when he gallivants about in front of windows, throw out his impressive collection of rotting Jack-O-Lanterns from previous Halloweens and take out his garbage, as it’s attracting wildlife (cue moose and Northern Exposure theme song).}}

Not excessive or immoderate; within due limits; proper.

a reasonable demand, amount, or price

Not expensive; fairly priced.

$20 a bottle is very reasonable for a good wine at a restaurant.

Satisfactory.

Adjective

(en adjective)

capable of being maintained or justified; well-founded

Back in the 1800s, many did not consider Darwin's theory of evolution to be tenable at all.

(of a defensive structure) capable of being defended against assault or attack; defensible