noun
Taurus (constellation); the Bull
Refers to the constellation Taurus in astronomy. Also used in astrology for the zodiac sign.
牡牛座は冬の夜空で見やすい星座です。
Taurus is an easy-to-see constellation in the winter night sky.
彼女の星座はおうし座です。
Her zodiac sign is Taurus.
Same meaning; おうし座 is a common mixed kana-kanji spelling, while 牡牛座 uses the kanji 牡牛.
From 牡牛 (おうし, 'bull') + 座 (ざ, 'constellation'). The reading ざ is a rendaku form of 座 (くら).