lasting or existing forever; without end or beginning.
eternal
a temporary period or arrangement until something permanent is established
interim
stop working
knock off
appear or happen suddenly or unexpectedly
crop up
an extremely long time
in/for donkey's years
a distinct period or stage in a process of change or development.
phase
something that belongs to a different time period from the one in which it exists; something outdated or misplaced in time
anochronism
end someone's employment, especially temporarily, because there is not enough work for them; stop doing or using something, especially for a short period of time
lay off
start working hard, especially when you should have done this earlier
knuckle down
used for saying that it is better to solve a problem now, rather tham leave it until later when it may be more difficult to deal with
a stitch in time (saves nine)
happening or done at the same time
simultaneous
done without delay; quick or punctual
prompt
spend time in a relaxed way when you have nothing else to do
while away
end or finish smth gradually; gradually reduce work before stopping completely
wind down
immediately or in a way that shows that you have no doubts about doing smth
at the drop of a hat
to come to an end; to no longer be valid or in effect.
expire
something that has not happened or been done by the expected or required time
overdue
help smn to get to the end of a difficult period of time, especially by giving them money until they can get
tide over
start doing smth in a very enthusiastic way
dive in
just in time to prevent smth bad happening
in the nick of time
no longer in use or no longer useful; out of date.
obsolete
related to managing or carrying out plans, decisions, or business operations
executive
continue doing smth in a determined way, despite difficulties, opposition or interruptions
press ahead
start doing or working on smth in order to achieve an aim outset
set out
very rarely
once in a blue moon