n. Any device that is less common than the normal ordinaries
the GNU version of the Collaborative International Dictionary of English
n. One of several heraldic bearings somewhat less common than an ordinary. See ordinary.
The Century Dictionary and Cyclopedia
n. In heraldry, a bearing of simple figure, often appearing, but not considered so common or so important as one of the ordinaries. See ordinary, 9.
Word Usage
"Minor geometric charges (subordinaries) are those which (except for the border) do not reach the edge of the shield; if used with an ordinary, the subordinary is placed on top."