barely; narrowly; only just; with difficulty
key; lock; key (to a problem, success, etc.); clue
unclear; obscure; unknown; unidentified; ignorance; lack of wisdom
about; roughly; generally; on the whole; completely; quite
tremendous; rapid; dramatic
artificial; man-made; human work; human skill; artificiality
worry; fear; anxiety; concern
economic; financial; economical; thrifty; frugal
rationality; reasonableness
perpetual motion machine; perpetual motion engine; perpetuum mobile
century; hundred years; (fig.) a long time
prosperous; flourishing; popular; widespread; active; lively
weak; frail; delicate; tender; unskilled; weak (wine)
concentration; diligence; asceticism; zeal in one's quest for enlightenment; adherence to a vegetarian diet
field; sphere; realm; division; branch
substitution; alternative; substitute
operation; management; handling; manipulating (to one's benefit); manipulation; influencing
gravitational sphere (of a celestial body); gravitational field
introduction; bringing in; installation; introduction (to a story, lecture, etc.); introductory part
still; yet; more; still more; furthermore; in addition
cheap; inexpensive; calm; peaceful; quiet
star (actor, athlete, etc.); celebrity; star (symbol); asterisk; (celestial) star
industry; (arch.) livelihood; (arch.) occupation
to assemble everything together; to do something as a group
assistance; support; subsidy; supplement; spotting (in weight training)
gorilla (Gorilla spp., esp. western gorilla, Gorilla gorilla)
common chimpanzee (Pan troglodytes); chimpanzee; chimp
orangutan (Pongo pygmaeus); orang-utan; orangutang
anthropoid ape; anthropoid; ape
in general; generally; mostly; gist; point; main idea
extrasolar; trans-Neptunian; outside the solar system