He seemed outwardly happy, but was actually quite sad inside.

outwardly 是由 outward（向外的）加上后缀 -ly 构成的副词。outward 由 out（外）和 -ward（向...方向）组成，表示"向外的"或"表面的"。 outwardly 意思是"表面上"或"从外表看"，强调外表与内在可能不一致。