Function: adjective
having a firm foundation in fact or logic FF1C; offered well-founded arguments to support his position FF1E;
Synonyms: cogent, good, just, justified, well-grounded
Related Words: sound, substantial, telling, valid; rational, reasonable, reasoned; fundamental, meaty, pithy
Contrasted Words: unjustified; insubstantial, invalid, unsound; irrational, unreasonable