WordNet records no synonym and no antonym for etiolation. It is the only member of each of its synsets, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
a pale and sickly appearance
“his etiolation signaled years in prison”
the act of weakening by stunting the growth or development of something
“the etiolation of the critical tradition”
Synonyms, antonyms and the broader and narrower relations for etiolation come from Princeton University’s WordNet. Full sources and licences.
(botany) the act of causing a plant to develop without chlorophyll by growing it without exposure to sunlight
“the etiolation of celery”