If thou faint
raphah (raw-faw')
to slacken (in many applications, literal or figurative)
in the day
yowm (yome)
a day (as the warm hours),
of adversity
tsarah (tsaw-raw')
tightness (i.e. figuratively, trouble); transitively, a female rival -- adversary, adversity, affliction, anguish, distress, tribulation, trouble.
thy strength
koach (ko'-akh)
from an unused root meaning to be firm; vigor, literally (force, in a good or a bad sense) or figuratively (capacity, means, produce); also (from its hardiness) a large lizard
is small
tsar (tsar)
adversary, afflicted(-tion), anguish, close, distress, enemy, flint, foe, narrow, small, sorrow, strait, tribulation, trouble.