The concept of little language seems to be echoed and amplified in the concept of Language Oriented Programming:
Wikipedia [1 ] says:
Given Tcl's extremely regular syntax and its habit of using little languages, it is worth considering Tcl as a platform for LOP.
2006-09-13 Shin The Gin - Coming from the Forth programming language, this sounds very familiar to me. In Forth you solve programming problems by developing a vocabulary of words, which in return is quite what you describe here. If You replace 'vocabulary' with 'namespace' and 'word' with 'command' then You're there.