adjective.
Which lasts a day, or approximately so.
adverb.
Throughout the day.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adjective.
lasting through an entire day
adverb.
during the entire day
Word Usage
"With her were two other student members of the Hillel Jewish Center taking part in daylong “getting to know the other” events between Muslim and Jewish student groups at USC."