Gratuitous
WordNet
adjective
(1) Without cause
"A gratuitous insult"
(2) Unnecessary and unwarranted
"A strikers' tent camp...was burned with needless loss of life"
(3) Costing nothing
"Complimentary tickets"
"Free admission"
WiktionaryText
Etymology
From < ,
Adjective
- Given freely; unearned.
- Not called for by the circumstances; uncalled for; without reason, cause, or proof; adopted or asserted without any good ground; unjustified.