1. be compatible, similar or consistent; coincide in their characteristics;
"The two stories don't agree in many details""The handwriting checks with the signature on the check""The suspect's fingerprints don't match those on the gun"
2. be equivalent or parallel, in mathematics
3. exchange messages;
"My Russian pen pal and I have been corresponding for several years"
4. take the place of or be parallel or equivalent to;
"Because of the sound changes in the course of history, an 'h' in Greek stands for an 's' in Latin"