Rashi defines the word in the mishna as waiting and anticipating, and compares the lashon to a phrase in mesechta kesubos 62b "the poor girl waited for nothing". The word appears earlier in the mesechta and Rashi does not define it. On daf 18b he defines it as just "waiting".
Question #1 why does he a- not translate it, b-translate it as waiting, and c-translate it on daf 38 as waiting and anticipating?
Question #2 why does Rashi use the phrase from kesubos to make his point, why not use the pasuk in the chumash bereshis 37:11 where Rashi defines the word "shamar" as waiting and anticipating?
Menachem Weiman, St. Louis, USA
After reviewing the appearances of the term "Shomeres Yavam" in the Shas, it seems like we can make the following list:
A. There are over 30 times just in Yevamos that the term appears.
B. It seems that when the term refers to a woman who can do Yibum but still did not do so, Rashi felt no need to explain it. It is self-explanatory.
C. Rashi does explain the term in the places you showed, and also in Sotah (18b) and Kidushin (27b), where he brings the verse from Bereishis, and he does so when it is significant that the woman is "waiting" or anticipating for the Yavam to marry her.
D. The Tosfos Yom Tov on this Mishnah (4:3) asks your question, and a Perush called Chidushei Maharich (Rav Yoel Chasid of Amshetslov) offers another distinction. When there is a "happy ending" and her anticipations are fulfilled, the verse from Bereishis is a good proof since, there, Yakov anticipated when Yosef's dreams would come true. Here, for example, the anticipation of the Yevamah were never fulfilled, and, on the contrary, she died in the end, and therefore Rashi looks for a better example (such as in Kesuvos) to show that also an unfulfilled anticipation is called "Shemirah."
All the best,
Aharon