11. A system of one or more computers configured to perform operations comprising: determining that a plurality of addresses cannot be geocoded by a geocoding system, wherein each address includes a plurality of terms; generating a plurality of variants of the addresses that can be geocoded by the geocoding system, wherein each variant of a respective address lacks a removed term included in the respective address; receiving a plurality of name terms for each variant provided by the geocoding system; associating each removed term with name terms received for all variants that lack the removed term, including determining, for each associated name term of each removed term, a count of the number of variants for which the geocoding system provided the name term; determining, for each associated name term of each removed term, whether the name term is an address term synonym for the removed term based at least in part on the count of the number of variants.
11. A system of one or more computers configured to perform operations comprising: determining that a plurality of addresses cannot be geocoded by a geocoding system, wherein each address includes a plurality of terms; generating a plurality of variants of the addresses that can be geocoded by the geocoding system, wherein each variant of a respective address lacks a removed term included in the respective address; receiving a plurality of name terms for each variant provided by the geocoding system; associating each removed term with name terms received for all variants that lack the removed term, including determining, for each associated name term of each removed term, a count of the number of variants for which the geocoding system provided the name term; determining, for each associated name term of each removed term, whether the name term is an address term synonym for the removed term based at least in part on the count of the number of variants. 20. The system of claim 11 , wherein the names for a geocoded location of a variant include one or more of: a street name, a city name, a region name, an International Organization for Standardization (ISO) region code, a country name, a postal code, and a high precision postal code.