crop vs lengthen

crop

verb
  • To mow, reap or gather. 

  • To remove the outer parts of a photograph or other image, typically in order to frame the subject better. 

  • To remove the top end of something, especially a plant. 

  • To cause to bear a crop. 

  • To beat with a crop, or riding-whip. 

  • To yield harvest. 

  • To cut (especially hair or an animal's tail or ears) short. 

noun
  • Tin ore prepared for smelting. 

  • The lashing end of a whip. 

  • A plant, especially a cereal, grown to be harvested as food, livestock fodder, or fuel or for any other economic purpose. 

  • A group, cluster or collection of things occurring at the same time. 

  • A photograph or other image that has been reduced by removing the outer parts. 

  • The foliate part of a finial. 

  • The head of a flower, especially when picked; an ear of corn; the top branches of a tree. 

  • An entire short whip, especially as used in horse-riding; a riding crop. 

  • An outcrop of a vein or seam at the surface. 

  • An entire oxhide. 

  • A rocky outcrop. 

  • A pouch-like part of the alimentary tract of some birds (and some other animals), used to store food before digestion or for regurgitation; a craw. 

  • A short haircut. 

  • The natural production for a specific year, particularly of plants. 

  • A group of vesicles at the same stage of development in a disease. 

  • The act of cropping. 

lengthen

verb
  • To make longer, to extend the length of. 

  • To become longer. 

How often have the words crop and lengthen occurred in a corpus of books? (source: Google Ngram Viewer )