This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Of, relating to, or based on a module or modulus.

adj. Designed with standardized units or dimensions, as for easy assembly and repair or flexible arrangement and use: modular furniture; modular homes.

adj. Mathematics Of or relating to fields having a characteristic greater than zero.

adj. Mathematics Of or relating to structured equivalence classes.

adj. Consisting of separate modules; especially where each module performs or fulfills some specified function and could be replaced by a similar module for the same function, independently of the other modules.

adj. Of or relating to a module or modules.

adj. Of or pertaining to mode, modulation, module, or modius

Pertaining to modulation; pertaining to or regulated by a module or a modulus.

where ad — bc = 1.

adj. constructed with standardized units or dimensions allowing flexibility and variety in use

"Surely the term modular just means that self contained modules are used, with common modules used for different systems or platforms."

standard   

modular ratio    modular focus    modular method of generation of quadrics    modular transformation of an elliptic integral    modular function    modular numbers    modular equation   

module    modularise    modularize    modularized   

nodular   

extensible    flexible    wireless    portable    standardize    specialize    high-performance    innovative    centralize    customizable