placo-comb. form
Stress is usually determined by a subsequent element and vowels may be reduced accordingly; see e.g.
placoderm n. and adj.Origin: A borrowing from Greek, combined with an English element. Etymons: Greek πλακ- , πλάξ , -o- connective.
Etymology: < ancient Greek πλακ-, πλάξ flat plate, tablet ( < an ablaut variant of the Indo-European base of floe n.) + -o- connective. Compare German Placo- (formations in which are found from at least the mid 19th cent.), French placo-.Found in a small number of scientific words from the mid 19th cent., earliest in placodont adj., an adaptation of a scientific Latin genus name; formations in English are found very shortly afterwards, apparently earliest in placoganoid adj. Combining with second elements of Greek origin. The position of the stress differs between compounds of placo- in accordance with the general stress patterns of English.
Chiefly
Zoology and
Palaeontology.
This entry has been updated (OED Third Edition, June 2006; most recently modified version published online March 2020).
comb. form