突先 is read as とっさき (tossaki) and means tip.
とっさき
tossaki
つっこむ
to delve into (a matter)
とつぜん
abrupt
とっぱ
breaking through
つきあたる
to come to the end of (a street)
つっこみ
straight man (of a comedy duo)
とつにゅう
plunging into (war, etc.)
つきあたり
end (of a street, hallway, etc.)
とっしゅつ
projection
とっしん
rush
つきあげる
to pressure one's superiors
とっき
protuberance
つきぬける
to pierce through