'level-topped' is a compound formed from 'level' and the past participle 'topped'. 'level' originates from Old French (and ultimately from Latin roots) as a word meaning a horizontal line or plane, while 'top' originates from Old English 'topp', meaning 'summit' or 'highest point'.

'level' entered Middle English with much the same sense of 'horizontal' or 'even'; 'top' came from Old English 'topp' to Middle English 'top', and the past participle 'topped' has long been used in compounds to indicate 'having a top of' or 'finished with a top', producing compounds like 'level-topped' in modern English.

Initially the elements referred separately to 'horizontal/even' ('level') and 'summit/uppermost part' ('top'); combined, they came to mean 'having a flat or even top surface'.