Definition of trigonometrical in US English:

trigonometrical

adjective

  • See trigonometry

    • ‘Astronomy, time-keeping and geography provided other motivations for geometrical and trigonometrical research.’
    • ‘But there were algebraic, trigonometrical, and simple Pythagorian solutions offered, too’
    • ‘Rather than using geometrical methods, as Ptolemy had done, al-Battani used trigonometrical methods which were an important advance.’
    • ‘He studied algebras and published papers on trigonometrical series.’
    • ‘It is perhaps surprising that the second most important trigonometrical function during the period we have discussed was the versed sine, a function now hardly used at all.’

Pronunciation

trigonometrical

/ˌtriɡ(ə)nəˈmetrək(ə)l//ˌtrɪɡ(ə)nəˈmɛtrək(ə)l/