Date: 201907
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
Airspace: Class B ZZZ
ATC / advisory: Ground ZZZ
Second aircraft: Commercial Fixed Wing
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Instrument
Human factors: Communication Breakdown; Confusion
Second reporter function: Pilot Flying; Captain
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Taxiway
Detector: Person Flight Crew; Person Air Traffic Control
When detected: Taxi
Result: Air Traffic Control Issued New Clearance; Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Procedure; Human Factors
Primary problem: Procedure

Narrative: We had just pushed off of the gate at ZZZ and were #2 in the alley for taxi out. It was a typical high traffic day at ZZZ; with one radio call following another too quickly to call for taxi. Eventually; the aircraft in front of us in the alley got clearance to taxi to [Runway] XXL via [Taxiway] XX; to hold short of [Taxiway] XX10; since there was a very long line on [Taxiway] XY waiting for takeoff. Immediately after that (without even having a chance for us to call) we were cleared with our full call sign to 'taxi up to and hold short of [Taxiway] XY' and I repeated this clearance with our call sign. This didn't really make sense to either of us in view of the long line; so the Captain held short of [Taxiway] XY on [Taxiway] XX7 but at a 45 degree angle with sufficient room to turn down [Taxiway] XX if needed. There was absolutely no radio silence available to ask for clarification; so we waited there for further guidance. A minute or so later; Ground said '(Company); I need you to pull up right to and hold short of [Taxiway] XY so that I can taxi aircraft behind you; I don't care if you block the service road (which is between [Taxiway] XY and [Taxiway] XX).' Note that they only said '(Company)' and not a full call sign and we inferred it was us from the previous recent clearance. I replied with our full call sign and 'pull up to and hold short of [Taxiway] XY.' We pulled up into [Taxiway] XX7 and waited a few minutes while several aircraft passed; but stayed on Ground frequency. Eventually; Aircraft Y was coming down [Taxiway] XY and it seemed that their wingtip would eventually impact our aircraft; so we jumped in on Ground to say 'Aircraft Y needs to stop or they will hit us!' Aircraft Y did not stop; but moved to the left side of [Taxiway] XY for clearance; which was minimal (they were apparently on Tower frequency). However; Ground then asked who we were and seemed to finally realize where we were; and in a very agitated voice said 'you need to switch to Tower! You are completely in the way and you have completely messed up the sequence!' I said 'well; we were just following instructions; sir.' And we switched to Tower who worked us in without further incident.


Second narrative: On taxi out with massive ground communications. Ground instructed us to taxi [via Taxiway] XX7 hold short of [Taxiway] XY for [Runway] XXL. We did that holding short of the crossing vehicle access road. Then then told us to move up and that they didn't care if we held short of [Taxiway] XY blocking the access road. We repeated the instruction with call sign. We noticed two large jumbo jets taxiing down [Taxiway] XY with wing spans that would be of a safety concern to my aircraft. Ground did not switch us to Tower. When Aircraft Y was continuing to taxi towards my aircraft; I instructed Ground that it was a safety concern. Ground seemed irritated and told us that we messed up his flow. Aircraft Y moved to the left on [Taxiway] XY and taxied safely past us. Ground switched us to Tower and we departed uneventfully.


Synopsis: B737 flight crew reported a ground conflict and problems communicating with ATC about their taxi instructions.