noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   The absorption of energy from a photon in raising a molecule (or chromophore) from the ground state; especially the first stage of photosynthesis in which energy is absorbed by chlorophyll uncountable, usually

Etymology

From photo- + activation.

Related phrases

ground state

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.