Retinal

google

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late Middle English: from medieval Latin, from Latin rete ‘net’.

wiktionary

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From retina +‎ -al(“of or pertaining to”).

From retina +‎ -al(“aldehyde”).

etymonline

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retinal (adj.)

"pertaining to or relating to the retina," 1798; see retina + -al (1). Related: Retinally.