Ostensibly

adverb/oss-TEN-suh-blee/

Meaning

In a way that appears true on the surface but may not be the real reason.

In context
The club was ostensibly for chess, though most members just came for the snacks.

Remember it

Ostensibly links to 'ostensible', meaning shown on the outside, hinting the truth may differ.

Use it well

Use to hint that the stated reason is a cover for the real one; signals mild doubt.