adjective
1.
Synonyms: free 5, chargeless, complimentary, costless, gratis
Related Word: voluntary, willing
2.
Synonyms: supererogatory , supererogant, supererogative, unasked, uncalled-for, wanton
3.
Synonyms: baseless , bottomless, foundationless, groundless, uncalled-for, unfounded, ungrounded, unwarranted
Related Word: indefensible, reasonless, unsupportable