Noun

• S: (n) plug-in, add-on (a software module that extends or enhances the capabilities of an existing application)
• direct hypernym / inherited hypernym / sister term
• S: (n) addition, add-on, improver (a component that is added to something to improve it) "the addition of a bathroom was a major improvement"; "the addition of cinnamon improved the flavor"
• direct hyponym / full hyponym
• S: (n) additive (something added to enhance food or gasoline or paint or medicine)
• S: (n) adjuvant (an additive that enhances the effectiveness of medical treatment)
• S: (n) food additive, artificial additive (an additive to food intended to improve its flavor or appearance or shelf-life)
• S: (n) afterthought (an addition that was not included in the original plan) "the garage was an afterthought"
• S: (n) annex, annexe, extension, wing (an addition that extends a main building)
• S: (n) ell (an extension at the end and at right angles to the main building)
• S: (n) attachment (a supplementary part or accessory)
• S: (n) hood, lens hood (a tubular attachment used to keep stray light out of the lens of a camera)
• S: (n) elongation, extension (an addition to the length of something)
• direct hypernym / inherited hypernym / sister term
• derivationally related form
• S: (n) accessory, appurtenance, supplement, add-on (a supplementary component that improves capability)
• direct hyponym / full hyponym
• direct hypernym / inherited hypernym / sister term
• derivationally related form