1. 立即的：offhand 即时的 | offhanded 立即的 | offhandedly 立即地

2. 即席的/无准备的：offhand /即时的/不加思索/ | offhanded /即席的/无准备的/ | offhandedly /即席地/随便地/

adj

1. casually thoughtless or inconsiderate

e.g. an offhand manner
she treated most men with offhand contempt

Synonym: offhand

2. with little or no preparation or forethought

e.g. his ad-lib comments showed poor judgment
an extemporaneous piano recital
an extemporary lecture
an extempore skit
an impromptu speech
offhand excuses
trying to sound offhanded and reassuring
an off-the-cuff toast
a few unrehearsed comments

Synonym: ad-libextemporaneousextemporaryextemporeimpromptuoffhandoff-the-cuffunrehearsed