'plainly-shaped' originates from the combination of 'plainly' and 'shaped', where 'plainly' means 'in a simple manner' and 'shaped' refers to the form or outline of something.

'Plainly-shaped' combines the adverb 'plainly' with the past participle 'shaped', forming a compound adjective.

Initially, it meant 'having a simple form', and this meaning has largely remained the same in modern usage.