・come across:〜と出くわす、偶然見つける
(When you come across a word that you don't know)
・even if:たとえ〜でも
(Even if you do decided that you would like to look the word up in a dictionary to be sure about its meaning)
・curious:好奇心をそそる、興味深い
(you probably don't need to stop and look up the word unless you are very curious about its meaning.)
◇When you do look up a word that you don't know
・rather:〜を選ぶ、〜を好む
・figure out:計算して合計（答え）を出す。算定する。見つけ出す。
(Rather, you should try to figure out which of these meanings fits the context in which you found the word. )
