Openly means without any attempt to hide it. Speak openly, openly hostile, live openly.
It implies there was a reason to conceal the thing, which is why openly gay carried weight and openly tall would be absurd. Openly hostile is stronger than hostile, because it says the person is not bothering to pretend.
1adverbopenlyWithout any attempt to hide it.
“He spoke openly about his struggle with depression in the interview.”
openly is a manner.
Old English openlice, from open plus -ly. Open comes from a Germanic root related to up.
Old English
openlīċe
Middle English
openli
English, today
openly
From Middle English openli, from Old English openlīċe. by surface analysis, en + open + ly.
Etymology from Wiktionary, CC BY-SA