The word "out-runs" refers to the act of surpassing or exceeding in speed or distance. Its antonyms are "lags behind," "trails," "falls short," and "loses." Lags behind means to be slower or fall behind in a race or competition. Trails mean to follow or move slowly behind someone or something. Falls short means to fail or not meet expectations. Finally, loses means to be defeated or not win in a race or competition. To strengthen one's vocabulary, it is essential to learn and have a good understanding of opposing words, such as antonyms. It helps in communication, writing, and comprehension of any given text.