tenser

adjective
  1. 1

    Showing signs of stress or strain; not relaxed.

    โ€œYou need to relax, all this overtime and stress is making you tense.โ€

  2. 2

    Pulled taut, without any slack.

Source: https://en.wiktionary.org/wiki/tense, https://en.wiktionary.org/wiki/tenser