台Taivo A Taiwan Mandarin dictionary

隔音符號

géyīnfúhào

ㄍㄜˊ ㄧㄣㄈㄨˊ ㄏㄠˋ

Simplified 隔音符号

1apostrophe, as used in pinyin orthography (i.e. to mark a boundary between two syllables, as in "dàng'àn" 檔案|档案[dang4 an4])

Keep 隔音符號 and it comes back until you know it.