fótathréimhseacht

== Irish == === Etymology === From fóta- +‎ tréimhse +‎ -acht. === Noun === fótathréimhseacht f (genitive singular fótathréimhseachta) (biology) photoperiodism ==== Declension ==== === Mutation === === Further reading === Ó Dónaill, Niall (1977), “fótathréimhseacht”, in Foclóir Gaeilge–Béarla, Dublin: An Gúm, →ISBN