A body is charged negatively. It implies that

A body becomes negatively charged when it acquires an excess of electrons relative to its number of protons. In an atom, protons are tightly bound within the nucleus and do not move during ordinary charging processes [t1, t8]. Conversely, electrons are labile and can be transferred between objects through methods like friction or contact [t8, t9]. When a neutral body gains or absorbs extra electrons from an outside source, the balance between positive and negative charges is disrupted [t2, t5]. Since electrons carry a unit negative charge, an accumulation of these particles results in a net negative charge, forming what is known as an anion at the atomic level [c1, t3]. Therefore, a negatively charged body implies it has acquired electrons from outside rather than losing protons, as the number of protons in a nucleus remains constant during such physical interactions [t3, t7].

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 25: Thunderstorm > 25.4. Lightning And Thunder > p. 348