A senior scientist is someone who has a lot of experience and knowledge in a specific field of science. They are often seen as experts and are usually in charge of leading research projects and guiding other scientists. Full definition
Senior scientists in your field may even have inside information on the kinds of ideas study sections are interested in funding. (sciencemag.org)
The opportunity to «ask senior scientists for advice» and to share experiences with other junior researchers in the process of establishing themselves can make the transition to independence much easier. (sciencemag.org)
That can be harder to come by, as senior scientists tend to lose contact with their students and postdocs who have left the field. (sciencemag.org)