Lean
Part of speech: adjective
Definition: slim; not fleshy. having little fat. Having little extra or little to spare. Of a fuel-air mixture, having more air than is necessary to burn all of the fuel; more air- or oxygen- rich than necessary for a stoichiometric reaction.
Part of speech: verb
Definition: To hang outwards. To press against.
Example sentence: People who lean on logic and philosophy and rational exposition end by starving the best part of the mind.
Insufficient
Part of speech: adjective
Definition: Not sufficient.
Example sentence: In the '90s, there was scant presidential leadership and insufficient domestic political mobilization for foreign policy grounded in human rights.