The 1940's silhouette followed on closely from the 1930's, but the influence of the war, with shorter straighter skirts to save on rationed material was a major one, that continued at least in Britain for most of the decade.
With women increasingly being economically active, as well as being in uniform, fashion also took on a more masculine look. This was the era of the shoulder pad, in its first incarnation before the 1980's! However it was often softened by a puffed or gathered sleeve,
Necklines varied but the buttoned or shirt waist top was a standout. What was not on show was any cleavage....certainly not in day wear.
Evening wear was a different story, especially post war, with sleek skirts and spaghetti straps featuring strongly at the end of the decade.....with the influence of Hollywood.
With hindsight the 1940's look was a very feminine one, emphasising the waist and the shoulders, but in a subtle way......