ground floor

noun

1. the floor of a building at or nearest to ground level.
2. Informal. an advantageous position or opportunity in a business matter, especially in a new enterprise: She took the job in the new company because she wanted to get in on the ground floor.

noun

1. the floor of a building level or almost level with the ground
2. get in on the ground floor or start from the ground floor informal
   1. to enter a business, organization, etc, at the lowest level
   2. to be in a project, undertaking, etc, from its inception