apsen. (教堂)半圓形拱頂附帶建築學術名詞拱點：天文學、物理學、航空太空、機械工程遠近[焦]點：天文學遠近點：航空太空環形殿：土木工程半圓形後殿：土木工程英文釋義a domed or vaulted recess or projection on a building especially the east end of a church; usually contains the altar