Definition of second-half:
(adj) :
Number-two; following after the first one with nothing between them. The ordinal number corresponding to the cardinal number two.
(adj) :
Next to the first in value, power, excellence, dignity, or rank; secondary; subordinate; inferior.
(n) :
Something that is number two in a series.
(n) :
Something that is next in rank, quality, precedence, position, status, or authority.
(adv) :
After the first occurrence but before the third.
(adv) :
(with superlative) After the first; at the second rank.