To write with a leading capital, marking a name or a start. Also to turn something held into working value.
From capital, Latin capitalis (of the head), from caput (head); a capital letter marks the 'head' of a word or sentence, and capital as money is the principal 'head' sum set apart from interest.
To write with a leading capital, marking a name or a beginning, and to turn something merely held into value put to work — two senses from one root.