愚鈍[gudon] stupidity
神経の鈍い[shinkeinonibui] insensitive
鈍い[osoi] slow
鈍化[donka] becoming dull
鈍角[donkaku] obtuse angle

鈍感[donkan] thickheadedness
鈍間[noroma] blockhead
鈍器[donki] blunt weapon
鈍行[donkou] ordinary train
鈍臭い[donkusai] slow (opposite of fast)

データの先頭[deetanosentou] beginning of data
一頭[ittou] one large animal (horses, cattle, etc.)
一頭立て[ittoudate] one-horse (carriage)
咽頭[intou] pharynx
駅頭[ekitou] station

音頭[ondo] leading a group of people
会頭[kaitou] society president
街頭[gaitou] in the street
核弾頭[kakudantou] nuclear warhead
巻頭[kantou] opening page of book