offhand
off
+
hand
https://gyazo.com/64a11cb7344a58c62bdd913811ab80bf
adjective
ungraciously
or
offensively
nonchalant
or
cool
in
manner
:
«…に対して» そっけない, 無愛想な «with»
e.g.
his offhand way of talking.
adverb
without
previous
thought
or
consideration
:
(よく調べないで)すぐに, 即答で
e.g.
I can't think of a better answer offhand.