deber - to owe; must, should, ought to

decidir - to decide, settle, resolve

decidirse - to decide, make up one's mind

decir - to say, tell

declarar - to declare, state; to bid [in cards]

decorar - to decorate, adorn

dedicar - to dedicate

dedicarse - to devote oneself, dedicate oneself, go in for, take up [carrer/interest in something]

defender - to defend