For zoning purposes, as covered by this Zoning Ordinance, "Lot" means a parcel of land of at least sufficient size to meet minimum zoning requirements for use, coverage and area, and to provide such yards and other open spaces as are herein required. Such lot shall have frontage on an improved public street, and may consist of:
(a) A single lot of record.
(b) A portion of a lot of record.
(c) A combination of complete lots of record, or complete lots of record and portions of lots of record or of portions of lots of record.
(d) A parcel of land described by metes and bounds.
In no case of division or combination shall any residual lot or parcel be created which does not meet the requirements of this Zoning Ordinance.