"Miner support" refers to the assistance or help provided to miners. It can include resources, services, or aid given to miners to enhance their work efficiency, safety, or overall well-being. Full definition
The outcome is yet unknown but the rule change will be governed by the percentage of miners supporting and running the new code. (dailybitcoinnews.com)
A chain split may occur should miners support various software. (bitcoinist.com)
The Segwit Core group remain adamantly opposed to any sort of native capacity increase, and have vowed to keep their own chain (Segwit1x) alive, although it is unclear if they will have enough miner support for the chain to survive. (calvinayre.com)