Slow \Slow\, v. t. [imp. & p. p. Slowed; p. pr. & vb. n. Slowing.]

To render slow; to slacken the speed of; to retard; to delay; as, to slow a steamer. --Shak. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

slowing

Source: WordNet (r) 2.0
 

Slow \Slow\, v. t. [imp. & p. p. Slowed; p. pr. & vb. n. Slowing.]

To render slow; to slacken the speed of; to retard; to delay; as, to slow a steamer. --Shak.

Source: Webster's Revised Unabridged Dictionary (1913)