先端 （センタン） pointed end, tip, point, cusp (of a leaf, crescent moon, etc.), apex (of a curve), forefront, vanguard, spearhead, leading edge

先鋭 （センエイ） radical, acute, sharp

肺尖 （ハイセン） pulmonary apex, apex of a lung

刀尖 （トウセン） tip of a sword

尖る （とがる） to taper to a point, to become pointed, to become sharp, to be on edge, to be nervous, to be irritable, to be touchy, to be sharp (of a voice, words, etc.), to be harsh, to be angry, to look displeased, to look sour, to be provocative, to be radical, to be rebellious

切っ先 （きっさき） point (of a sword, etc.), pointed verbal attack

雛頭 （ひなさき） slightly protruding part of the front of an eboshi, clitoris

鋭い （するどい） sharp (knife, claws, etc.), pointed, sharp (pain, tone, etc.), acute, stabbing, cutting (remark, criticism, etc.), stinging, biting, fierce (attack), pointed (question, look, etc.), piercing (gaze), shrill (sound), keen (intuition, sense of smell, etc.), acute, sharp (eye, mind, etc.), astute, shrewd, discerning, penetrating (insight, question, etc.), perceptive