Glad

adj.joyful, calmwarm

Meaning 1

Pleased and relieved about a particular event or fact.

Reach for it when expressing simple personal happiness, gratitude, or welcome

We are glad the footbridge reopened before the school term.

everyday
happy
general positive feeling is the natural choice
not when Happy can describe a lasting state; glad usually responds to something specific.
everyday
relieved
the good feeling comes from danger or worry ending
not when Relief can occur without joy, which glad normally includes.
warm
delighted
the happiness is strong and openly felt
not when Delighted overstates mild relief or quiet approval.
professional
pleased
approval or satisfaction should sound measured
not when Pleased is more reserved and may feel distant in an emotional reunion.

Willing to do something with genuine pleasure.

Reach for it when offering help or agreement in a warm, uncomplicated way

Iris was glad to show the new volunteer where the supplies belonged.

everyday
eager
anticipation and readiness are stronger than simple willingness
not when Eager may promise more enthusiasm than the person actually feels.
warm
happy to
a friendly offer should sound natural and current
not when In repeated business copy, happy to can become formulaic and vague.
professional
willing
consent or readiness matters more than emotion
not when Willing may be reluctant; glad to help signals pleasure.
formal
amenable
someone is open to a proposal or request
not when Amenable sounds detached and does not convey pleasure.

The definition and the example on this page are written here. The dictionaries above ground which meaning is being described, not the wording.