(electric) circuit; racing circuit
moderate; reserved; conservative; humble; mild-mannered; self-effacing
one's field of expertise; one's strong area
talkativeness; garrulity; loquacity
underground; below the ground; world of the dead; the grave; underground (activities, movement, etc.); secret
approximately; about; promise; appointment; shortening; reduction
to incline; to lean; to devote oneself to; to concentrate on; to ruin; to squander
feeling of solidity; three-dimensionality; drawing highlights
divide into four pieces; one fourth
one revolution; one rotation
(right at the) side; just beside
central part; heart (of a city)
metre; meter; meter; gauge
to dive (into or under water); to get under; to get into; to hide oneself (esp. from the government); to conceal oneself
direct access; random access
to tear; to rip; to break through (cordon, opponent's defense, etc.); to breach; to defeat; to beat; to break (e.g. silence)
restoration; restitution; rehabilitation
impossible to do (although wants to)
putting into operation; invocation
action; operation; effect; function
participation; taking part in; participating in; being concerned in
making use of; application; practical use; operation; handling; steering (esp. a boat)
prototype; model; pattern; archetypal
preservation; conservation; storage; saving (e.g. to disk)
whenever necessary; as needed; as required; at any time; at all times
original and copy (of a document); principal and vice- (e.g. chairman and vice-chairman)
system; lineage; ancestry; group (e.g. of colors) (colours); family (e.g. of languages); close (evolutionary) relationship
hard to understand; incomprehensible; unintelligible
eyes sparkling; with shining eyes; for one's eyes to gleam
default settings; initial settings; initial configuration; initialization; initialisation
restoration; repair; mending
independence; self-reliance; independence (e.g. of a nation); freedom; separation; isolation
going down; fall; knocking down (in boxing); flooring; being out of action (due to illness, exhaustion, etc.); being down (e.g. with a cold); going down (of a computer system, server, etc.)