D defs.my
Entry 2 senses Webster, 1913

Chiefly

/chēf'-lē/ · Chief·ly · IPA /ˈtʃiːf.li/
01 adv. In the first place; principally; preëminently; above; especially.
  1. 1.
    In the first place; principally; preëminently; above; especially.
    “Search through this garden; leave unsearched no nook; But chiefly where those two fair creatures lodge.” Milton.
  2. 2.
    For the most part; mostly.
    “Those parts of the kingdom where the . . . estates of the dissenters chiefly lay.” Swift.