Word family noun trainee trainer training retraining adjective trained ≠ untrained verb train retrain
From Longman Dictionary of Contemporary Englishtrainertrain‧er /ˈtreɪnə $ -ər/ ●●○ noun [countable] 1 SETsomeone who trains people or animals for sport or work → coach a racehorse trainer► see thesaurus at teacher2 
British EnglishDC a type of strong shoe that you wear for sport SYN tennis shoe American EnglishExamples from the Corpus
trainer• And how could you buy your kid New Balance trainers when everyone is wearing Reeboks right now?• But trainer Hannon said any stiffness would have had no connection with the broken leg which led to Mr Brooks' death.• She kicked her trainers under the seat, in case Brown Owl had funny ideas like Mum.• Alongside the factual overview for managers, trainers are concerned to sharpen the managers' interpersonal skills.• Many companies now pay outside trainers to come in and teach management skills to their staff.• No perfect-body personal trainer or low-fat chef for me.• One of the traditional remedies of racehorse trainers was firing.• The standard 0.50 powered machine makes a superb trainer.• I work as a teacher trainer.• She called Kim, the trainer, on the phone and, in between uncontrollable sobs, told her what was happening. 