Feeling safe and secure in your body

to be properly grounded means that you experience a flow of giving and receiving that connects you with the Earth. 
The giving flow means that you express yourself on Earth in a way that manifests your unique soul energy in your daily activities so that you experience joy and fulfillment. The receiving flow means that you enjoy what life has to offer and that you say "Yes" to being fully present on Earth- here and now. Not being fully grounded means that the inspiration in your heart does not, or just barely, manifests on Earth, so you are not able to give earthly form to your creativity.