1. (noun) vertical space available to allow easy passage under something

• clearance
• headroom

2. (noun) forward movement

• head

1. (noun) vertical space available to allow easy passage under something

• elbow room
• room
• way

2. (noun) forward movement

• advance
• progress
• progression

1. (noun) forward movement

• channelise
• channelize
• direct
• guide
• head
• maneuver
• manoeuver
• manoeuvre
• point
• steer
• head
• head
• lead