This is a brilliant word I found out about when reading Alec Motyer’s Psalms of the Day.
In Psalm 18 it is translated variously wholehearted and perfection and Alec Motyer gives the following translation notes:
Psalm 18:23: tamiym is the perfect integration of all the parts and aspects of a person, undivided commitment.
18:25 That which is as it should be in all its parts. Hence ‘perfect’, ‘complete’. Possibly ‘wholehearted’ in loyalty to Yahweh and receiving ‘wholehearted’ divine devotion in return.
18:30 – see notes above – The Lord’s way is the perfect and perfectly integrated lifestyle, the exactly right way for every aspect of life.
Also verse 32…
Dear Father, thank you that you are tamiym (I’m sure the grammer of that is wrong!!) and please help me to be more wholehearted towards you. Amen.