Unnecessary and unwarranted; "a strikers' tent camp...was burned with needless loss of life"
(gratuitously) in an uncalled-for manner; "he insulted us gratuitously"
Given freely; unearned; Not called for by the circumstances; uncalled-for; without reason, cause, or proof; adopted or asserted without any good ground; unjustified
(adj.) uncalled for, unwarranted (Every evening the guy at the fish and chip shop gives me a gratuitous helping of vinegar.)
Without consideration, e.g., in the nature of a gift that's given with nothing whatever expected in return.
(adj) - given freely, unwarranted, uncalled for
Made or granted without monetary or other consideration.