Surviving spouse means the husband or wife living with or dependent for support upon a deceased employee at the time of his or her death, or living apart for reasonable cause or because of the deceased employee's desertion, unless otherwise defined under the FECA for the specific benefit such as the FECA death gratuity at 5 U.S.C. 8102a.
20 CFR § 10.5
Certain words and phrases found in this part are defined in this section or in the FECA. Some other words and phrases that are used only in limited situations are defined in the later subparts of the regulations in this subchapter.