Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† tŏnus, i, m.,  =  τόνος. 
- I.  The stretching, straining of a rope: mollior, vehementior, Vitr. 10, 10, 6. 
 
- II.  Trop. 
 
- A.  Lit., the sound, tone, of an instrument, Vitr. 5, 4; Macr. Somn. Scip. 2, 1 med.; Mart. Cap. 9, § 959.
Of the tone of a syllable, accent, Nigid. ap. Gell. 13, 25, 1 sq. 
- B.  Transf. 
 
- 1.  Like our tone, in painting, of the natural color of an object, Plin. 35, 5, 11, § 29.
 
- 2.  For tonitrus, thunder, Sen. Q. N. 2, 56, 1.