be short of, not have, be deficient in, need, require
Short, shy.
deficiency
be without
Another word for "lack of interest" is apathy or indifference. These both basically refer to a person who is uninterested, unresponsive or impassive. Another word to describe this sort of person could also be perfunctory.
Lack, want,
incommunicado
Inaction??
lack dearth
lethargic
lacking skill
Harsh truth
Lazyness
to lack to deprive to sacrifice
benighted; lack of knowledge, uncultivated; etc;