How to say "booster" in Japanese

• ブースター
  nounThe direct loanword, covering the same ground as English 'booster': a device or thing that boosts something. For the plain, non-figurative senses, this is the word to reach for.
• 昇圧機しょうあつき
  nounSpecifically an electrical booster: equipment that boosts current or voltage. Use it only for this technical sense, never for boosters in general.
• 倍力ばいりょく
  noun, prenominal modifierA mechanical term for force multiplication — the sense that overlaps with 'servo'. It fits only when 'booster' means something that boosts mechanical force, not the other senses.
• 提灯持ちちょうちんもち
  nounThe figurative sense for people: someone who 'boosts' another person by flattering and praising them — a flatterer or brown-noser, literally a lantern holder. Not used for devices or machines.

Choose 「ブースター」 for the general 'thing that boosts' sense, 昇圧機 for boosting electrical current, 倍力 for mechanical force multiplication, and 「提灯持ち」 for a person who boosts someone through flattery.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• ブースターbooster
• 昇圧機しょうあつきbooster (e.g. of current)
• 倍力ばいりょくservo
• 提灯持ちちょうちんもちflatterer