WordNet sense 1 (the state of being contented with your situation in life):

contentedness

WordNet sense 2 (the amount that can be contained):

capacity

WordNet sense 3 (what a communication that is about something is about):

message, substance, subject matter

WordNet sense 4 (the sum or range of what has been perceived, discovered, or learned):

cognitive content, mental object

WordNet sense 5 (something (a person or object or scene) selected by an artist or photographer for graphic representation):

subject, subject, depicted object

WordNet sense 6 (marked by excessive complacency or self-satisfaction):

smug

WordNet sense 7 (filled with satisfaction):

satisfied

WordNet sense 8 (contented to a fault with oneself or one's actions):

complacent

WordNet sense 9 (satisfied or showing satisfaction with things as they are):

contented