Stalwart

/ˈstɔːlwərt/ adjective easy

Loyal, dependable, and firm in one's support, especially under pressure.

Even when the team was losing, its stalwart fans kept filling the stadium every single week.

Memory Trick

Stalwart descends from old words meaning 'stall' (place) plus 'worth' -- a stalwart supporter is worth keeping in place because they never budge.