骨幹こっかん

kokkan

1. Not essential; Not a mainstay

1. Was key; Was central

1. Core; Mainstay

1. Core; Key

1. It is not a main part.; It is not a key component.

1. Not a key member.; Not essential.

1. Was a key member.; Was the core.

1. Backbone; Core

1. Is not a mainstay.; Is not a key member.

1. Wasn't the core; Wasn't essential

1. Likely the core; Probably the mainstay

1. Was not a core member.; Was not a key person.

1. Wasn't a key member.; Wasn't the backbone.

1. Likely; Probably

1. Was not a core member.; Was not a key person.

1. If/when backbone; If/when key member

1. If it is the core; If it’s the trunk

1. If/when backbone; If/when core