overslow

/ˌoʊvərˈsloʊ/
adjective
  1. Too slow; slower than necessary or desirable.
    • The overslow service at the restaurant frustrated the customers.
    • His overslow walking pace made us late for the movie.
    • The internet connection was overslow, making it impossible to stream videos.
Antonyms
verb
  1. To make or become too slow; to slow down excessively.
    • The driver overslowed the car when approaching the curve.
    • If you overslow the machine, it might stop working altogether.
    • The heavy rain overslowed the traffic on the highway.