Sentence:  He said a reversionary <WSD>proffer</WSD> – saying the property would revert to its prior zoning if certain benchmarks were not met by the developers – was brought up in a conceptual discussion in a pre-application meeting in May 2014 with the developers, but did not progress beyond that. 
Meaning of the word marked with <WSD> tags:  An offer made; something proposed for acceptance by another; a tender.