difficult to ...; hard to ...
behavior; behaviour; manner; attitude; bearing
cleaning; sweeping; dusting; scrubbing
washing; laundry; relaxing; taking a break
strict; severe; stern; rigid; rigorous; tough
mental preparedness; being braced for; being steeled for
to become loose; to slacken (e.g. rope); to become less tense; to relax; to slacken (e.g. coldness, supervision); to become lax; to become softer (e.g. ground, facial expression)
severe; strict; hard (to do); difficult; intense (e.g. cold); harsh (weather)
to put back; to return; to vomit; to throw up; to recover (of a market price)
power; might; authority; influence
control (of a machine, device, etc.); control (over an opponent, one's emotions, etc.); governing; management
strength; power; proficiency; ability
component; factor; item (e.g. in list); element (e.g. in array); member (e.g. data structure)
not exceeding; and downward; below (e.g. standard); under (e.g. a level); the below-mentioned; the following
bill; bill of sale; tab (for later payment); credit; contact move (in go); direct attack to an enemy stone; sound effect produced by striking with clappers a wooden board in kabuki
item; heading; category; headword (in a dictionary, encyclopedia, etc.); entry
potentiality; likelihood; possibility; availability
discouraged; dispirited; despondent
term; terminology; wording; choice of words; phraseology
mouthful; morsel; gulp; sip; one word; in short
continuously in some state (for a long time, distance); throughout; much (better, etc.); by far; far away; long ago
use; exercise (of one's right, authority, power, etc.)
obsession; fixation; complaining; criticizing; speciality (e.g. of restaurants)
most; highest; maximum; best; wonderful; finest
person; -er; (arch.) expert; (arch.) geisha; (arch.) prostitute
necessary; needed; essential; necessity; need; requirement
to respond; to answer; to meet (e.g. demands, expectations); to affect; to take a toll; to strike home
the best one can do; one's best effort; with all one's might; to the best of one's ability
plot of land; lot; soil; locality; region; place
to become thin; to lose weight; to reduce (one's) weight; to be barren; to be infertile; to be sterile
theory; doctrine; opinion; view; rumour; rumor
surrounding countries; neighboring countries; neighbouring countries
quite; very; 10^48; quindecillion
revelation; manifestation; appearance; expression (e.g. in molecular biology; protein expression or gene expression)
everyone; everybody; all; everything; all
head; hair (on one's head); mind; brains; leader; chief; top