A dictionary of Confusable Phrases: More Than 10,000 Idioms and Collocations

Note: 
Neither expression correlates in meaning with the phrase
with all one’s strength
— using as much physical effort as one
can: He looped the rope over the branch and pulled with all
his strength.
at full time • in the fullness of time
at full time —reaching the normal mass or dimension: At
full time the fetus weighs from six and one-half to eight
pounds.
Note: 
The expression does not correlate in meaning with the
phrase full time—
1
. the regular number of hours allotted to daily
or weekly work: All the factories we visited were running full
time. 2. (also: high time) time when smth. should be done at
once: The vessel is going to pieces, and it is full time for all
who can, to leave her.
in the fullness of time —at the proper or destined time: In
the fullness of time, your children and your in-laws become
friends.
at hand • in hand
at hand —(also: on hand) within easy reach; close by: Keep
a good dictionary at hand as you write. Proofread carefully.
in hand —
1
. said of smth. being dealt with: If you apply
yourself to the job in hand, you’ll soon finish it. 2. (also: on
hand) in one’s possession: Sometimes it is a better idea to bor-
row money than to wait until you have the money in hand.
at hazard • on the hazard
at hazard —
1
. at random; without plan: The following ex-
amples were selected at hazard. 2. at stake; in danger: Their
worldly interests were at hazard.
on the hazard — = at hazard 2: Messala’s whole fortune was
on the hazard.
at high pressure • under high pressure
at high pressure —
1
. (of matter) when strongly pressed: Steam
and oxygen at high pressure are introduced at the lower end
of the gasifier. 2. acting with great energy and speed: As for
Robert, he, of course, was living at high pressure all round.
under high pressure —
1
. = at high pressure 
1
: The new material
loses its resistance only under high pressure. 2. when strongly
persuaded or compelled: Working under high pressure for sus-
tained periods results in stress.