The word "extender" refers to an object or device that prolongs or lengthens something. Synonyms for this word include "expander," "prolonger," "elongator," or "stretching device." A "booster" also serves as a synonym for the word "extender," as it amplifies signals or promotes growth. Another synonym for an "extender" is a "reacher," which refers to an object used for accessing out-of-reach items. Additionally, a "continuer" also serves as a synonym for this word as it implies the continuity or continuation of something. These synonyms can be used interchangeably depending on the context and specific situation in which the concept of prolonging or enlarging something is being discussed.