テンションtenshon

1. nounspirits; excitement; energy level; (good) mood
2. noun, physicstension
3. nountension (mental strain); anxiety

• Synonym緊張きんちょうNeutralNeutral word for nervousness or mental strain, as in 「試験で緊張する」; 「テンション」 colloquially covers the level of excitement rather than anxiety.
• Related張力ちょうりょくWrittenWritten term for physical tension or tensile force, as in 「表面張力」; it has no emotional sense, whereas 「テンション」 colloquially refers to how high one's spirits are.
• AntonymリラックスNeutralLoanword meaning to relax or unwind; it is the opposite of the keyed-up, excited state that colloquial 「テンション」 describes.
• Antonym弛緩しかんWrittenWritten term for slackening, as of muscles; it opposes 「テンション」 only in the physical tension sense, not the mood sense.

Use 「テンション」 for colloquial talk of excitement or mood, as in 「テンションが上がる」 and 「ハイテンション」. For physical tension say 「張力」, for nervousness 「緊張」, and for relaxing 「リラックス」; written 「弛緩」 is its opposite in the physical sense.

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

1. 緊張きんちょう。不安ふあん。
2. 張力ちょうりょく。
3. 気分きぶんの盛り上もりあがり。