Harold Best defines worship most broadly, reminding us that there is a commonality to all aspects of “worship,” whether the object be worthy of our worship or not.

Worship is
the continuous outpouring of
all that I am,
all that I do, and
all that I can ever become
in light of a chosen or choosing god.

Jonathan Gibson focuses on the normative aspect of worship. It is explicitly Trinitarian, and he makes the rare moves of including angelic worship; including the past, the present, and the future; and embedding a worshipful response within the definition itself.

Worship is
the right, fitting, and delightful response of moral beings
—angelic and human—
to God the Creator, Redeemer, and Consummator,

for who he is as one eternal God in three persons—Father, Son, and Holy Spirit—and
for what he has done in creation and redemption, and
for what he will do in the coming consummation,

to whom be all praise and glory, now and forever, world without end. Amen.

Daniel Block discusses the nature of true worship, emphasizing the acts of worship.

True worship involves
reverential acts of homage and submission before the divine Sovereign
in response to his gracious revelation of himself and
in accord with his will.

Bruce Leafblad puts the goal of communion with God front and center and includes the grace of God and the use of both mind and heart.

Worship is
communion with God
in which believers, by grace, center their
minds’ attention and
hearts’ affection
on the Lord,
humbly glorifying God in response to his greatness and his word.

John Piper distinguishes between the inner essence and the outward expression of worship, connects the notional and the affectional, and uniquely (among the definitions cited here) including note only acts of praise but acts of love as well.

The inner essence of worship is
to know God truly
and then respond from the heart to that knowledge by
valuing God,
treasuring God,
prizing God,
enjoying God,
being satisfied with God above all earthly things.

And then that deep, restful, joyful satisfaction in God overflows in
demonstrable acts of praise from the lips and
demonstrable acts of love in serving others for the sake of Christ.

Bob Kauflin gives a definition that includes the use of mind, affection, and will and is one of the few that explicitly mentions the Holy Spirit.

Christian worship is
the response of God’s redeemed people to His self-revelation that exalts God’s glory in Christ
in our minds, affections, and wills,
in the power of the Holy Spirit.