The word [semana](javascript:void(0)) in Spanish means "week" in English. It refers to a period of seven days, often used in calendars and to measure time. For example, "Semana 1" would mean "Week 1" and can denote the first week in a year, month, or a specific context like pregnancy. More specifically, "Semana 1" can refer to different contexts:

• In terms of a calendar year, "Semana 1" typically starts from the end of December or early January, marking the first full week according to standard ISO week date systems where weeks start on Monday and end on Sunday.
• In pregnancy, "Semana 1" is counted as the first week of pregnancy, which corresponds to the menstrual period and the preparation for ovulation, even before conception occurs. It counts as part of the 40 weeks of a typical pregnancy duration, but the embryo is not yet formed during this week.

So, the word is a basic unit for grouping seven days and is extensively used for both general time tracking and specific time counts like pregnancy timelines.