due 到期的 预定的 约定的
The bill was due two weeks ago, but I forgot to pay it
Their plane is due in 15 minutes.
cursory 仓促的 hurried (curs跑+ory)
The reviewer gave a cursory report about the uninteresting book.
perennial 长久的 永远的 permanent, long-lasting, year-round
chronic 长期的 慢性的 recurring, periodic (chron时间+ic)
Mike said a chronic disease troubled John in his whole life.
lasting 持久的 enduring, long-term, continuing
everlasting 永恒的 持久的
hasty 匆忙 rushed
transitory 短暂的 temporary, momentary
transient 短暂的 过路的 temporary, short-term
He made a transient stay at the hotel.
obsolete 过时的 偶然的 disused, outmoded (ob不+solete使用)
This new computer rendered my old one obsolete.
extemporaneous 即席的 impromptu, improvised
I gave an extemporaneous lecture because the invited speaker was late.
urgent 紧急的 迫切的 imperative
It is urgent that food and clothing be sent to the refugees.
pressing 紧迫的 urgent
immediate 立即的 instant (im无+medi中间+ate)
forthright 立即的
The critic  gave the forthright criticism to the director of the film.
offhand 临时的
I gave an offhand guess that it's about three o'clock.
temporal 一时的暂时的 transient, momentary
temporary 临时的 momentary, make-do
contemporary 当代的 同时代的
impromptu 临时的 即兴的 extempore, improvised (im不+promptu时间 不在时间表内)
The pianist gave an impromptu performance at the party.
occasional 临时的 偶然的
The silence was broken by an occasional scream.
punctual 守时的
Mary is punctual; she would never be late for an appointment.
instantaneous 瞬间的 即刻的 ephemeral
subsequent 随后的 后来的 following, later
Subsequent events proved the man to be right.
current 现今的 present
Recent reports will give the most current news about the accident.
He reads the newspaper every day to know the current events.
concurrent 同时发生的 sumultaneous
There were several concurrent attempts to climb the mountain.
extant 现存的 existing
nocturnal 夜间的 nighttime, nightly (noct夜+urnal diurnal 白天的)
An owl(猫头鹰) is an nocturnal bird, while a sparrow（麻雀） is diurnal.
former 以前的 ago, previous
My former students still kept in touch with me through e-mail.
formerly 从前 原来 preceding, foregoing
previous 以前的
previously 从前 以前 earlier, formerly
eternal 永恒的 everlasting, perpetual
The bride and groom pledged their eternal love to each other.
permanent 永久的 constant, continuous
Anne took a permanent position with the law firm.
abiding 永久的 永恒的 enduring, lasting
dated 有年头的 陈旧的
The dated movie was still quite entertaining.
overdue 逾期的 tardy, late
tentative 暂时的 temporary
Tentative measures have been taken to settle these refugees.
beforehand 事先地 in advance
Please make a reservation at the restaurant beforehand so we don't have to wait.
simultaneously 同时地 at the some time, concurrently
The two balls, big and little, hit the ground simultaneously.
recently 最近地 lately, currently
lately 最近
duration 持续时间 为期 length
epoch 纪元 时代 age，era
interlude 间隔 插曲 interval, episode
era 时代 时期 period, age
schedule 时间表 计划表 calendar, timetable
juncture 时刻
session 一段时间 一次
A very dehydrated man can not drink too much water at one session, or he will get himself killed through water intoxication
elapse （时间）消逝 go by, pass
Time elapsed slowly while I waited for the bus.
concur 同时发生
After hearing my point, Bill concurred(同意) with me.
improvise 即席而作 extemporize
The actor improvised a scene based on an audience's suggestion.
sunchronize 同时发生 concur
They synchronized their steps.
abruptly 突然地 唐突地 suddenly