本務 is read as ほんむ (hommu) and means duty.
ほんむ
hommu
にほんけいえいざいむけんきゅうがっかい
Japan Finance Association
ほんとう
proper
ほんしょう
true character
ほんぶ
headquarters
ほんばん
production environment
ほんとうに
really
ほんのう
instinct
ほんちょうし
keynote (esp. shamisen)
ほんかいぎ
plenary session
ほんかく
original method
ほんかくか
regularization
ほんけん
this matter