なまけて時を過ごしてはならない。

to be idle; to slacken; to neglect (e.g. one's work)

time; hour; moment; occasion; case; chance; opportunity; season; the times; the age; the day; tense

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to pass (time); to spend; to overdo (esp. of one's alcohol consumption); to drink (alcohol); to take care of; to support; to overdo; to do too much; to ... without acting on it

if ... then; when; and; why don't you...?; the more (one does something); because; since