a head as hard as a stone / stubbornness and inflexibility / an inflexible person

specialist; expert

an iris (part of the eye)

alternative form of デュース (dyūsu, “deuce”)

(government, politics, uncommon) president / (government, politics) generalissimo / (historical) Führer - Adolf Hitler when the chancellor of Nazi Germany

amber (fossil resin)

sunlight

(rare) a mole (burrowing insectivore) / (rare) an earthworm (worm (animal)) / (figuratively) an outstanding horse; an excellent horse; a famous horse (by metaphor from the meaning of the kanji)

pessimist

(sports) match, game