鞍部 is read as あんぶ (ambu) and means col.
あんぶ
ambu
とるこあんぶしゅよう
sellar tumour
くら
saddle
あんば
saddled horse
かんぶ
management
いちぶ
one copy (e.g. of a document)
ほんぶ
headquarters
ないぶ
interior
がくぶ
department of a university
ぜんぶ
all
ほくぶ
northern part
とうぶ
eastern part
がいぶ
outside (e.g. of a building)