To make glad; to cause gladness or happiness in someone.
From 'glad' plus '-ify' suffix meaning to make or cause to be; follows the pattern of verbs like 'clarify' and 'beautify.'
The '-ify' suffix is magical—adding it to almost any adjective creates a verb, which is why 'gladify' *should* work even though we don't use it (we say 'gladden' instead).
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