centre

[1]	focus , converge , meet , concentrate , cluster
[2]	center
[3]	concentrate , focus , center , pore , rivet

[1]	middle , core , heart , nucleus , focal point , hub , pivot , nave , mid-point
[2]	center , middle , heart , eye
[3]	center , midpoint
[4]	center
[5]	center
[6]	kernel , substance , core , center , essence , gist , heart , heart and soul , inwardness , marrow , meat , nub , pith , sum , nitty-gritty
[7]	center , center of attention , centre of attention
[8]	center , nerve center , nerve centre
[9]	center